Structural interrupter and limit stop for remotely controlled turrets



June 29, 1954 Filed Oct. 12, 1951 L. L. JACKSON EI'AL STRUCTURAL INTERRUPTER AND LIMIT STOP FOR REMOTELYCONTROLLED TURRETS 2 Sheets-Sheet 1 ZNVENTOR5 455727? L..//7a(.so/v GORDON emansxa/akst F250 Asa/027A! ATTORNEY June 29, 1954 JACKSON ET AL 2,682,200

r STRUCTURAL INTERRUPTER AND LIMIT STOP F OR REMOTELY CONTROLLED TURRETS Filed Oct. 12, 1951 2 Sheets-Sheet 2 INVENTORs 5 u m I 55 724 (J/7mm H W 9 saweaawwwsz H H Fmm swam/v;

ATTORNEY Patented June 29, 1954 UNITED STATES PATENT OFFICE STRUCTURAL INTERRUPTER AND LIMIT STOP FOR REMOTELY CONTROLLED TURRETS Lester L. Jackson,

Towson, and Gordon P.

Application October 12, 1951, Serial No. 251,106

4 Claims.

This invention relates to a control system for turret mounted guns, and more particularly, to a system for preventing the gun barrel from striking any portion of the structure on which the turret is mounted, by automatically altering the path of the gun as the gun barrel approaches any protruding part of the mounting structure.

In a gun turret installation in which the gun is mounted so as to be rotatable about a pair of perpendicularly related axes, the turret itself being rotatable about a generally vertical axis, and the gun being rotatable in elevation about a horizontal axis, it is necessary to provide means to prevent the gun barrel from being depressed far enough to strike any portion of the structure on which the turret is mounted. It is also necessary to provide means to prevent the gun barrel from being moved so as to strike any obstacle normally projecting into the region through which the gun might move while tracking a target. With ordinary limit stops of the type usually provided for such a purpose, the operator must manipulate the controls to cause the gun to move around any obstacle extending into its path. This is highly undesirable since the operator must realign the sight with the target after the obstacle has been cleared. If an ordinary cam is used to elevate the gun far enough to clear the obstacle, without the azimuth motion being altered, the path of the gun barrel cannot be made to conform closely to the contour of the obstacle and the field of fire coverage of the gun is therefore materially reduced.

Obviously, it would be highly desirable to provide a system of gun control in which the path of the gun barrel is automatically altered to clear any obstacle, control of the gun being returned to the operator once the obstacle has been cleared, thus allowing the operator to continue to track a target with the sight while the path of the gun is being altered, the gun automatically being realigned with the sight after the obstacle has been cleared without the necessity for any additional manipulation of the controls by the operator.

It is further desirable, in such a system, to cause the path of the gun barrel around an obstacle to conform closely to the shape of the ob stacle in order to minimize the region into which the gun cannot be moved, thereby increasing the field of fire coverage of the gun to a maximum.

It is an object of this invention to provide a systern for a turret mounted gun which will automatically alter the path of the gun so that it will clear any obstacle normally extending into its path.

It is another object of this invention to provide a system as described above in which the rates of elevation and azimuth movement are automatically varied to cause the path of the gun 2 around an obstacle to conform closely to the profile of the obstacle, thus minimizing the region into which the gun may not be moved.

It is a further object of this invention to provide 'means for limiting the elevation movement of a turret mounted gun so that it cannot be depressed below a predetermined angle, which may vary with the position of the gun in azimuth, thereby preventing the gun barrel from striking the structure on which the turret is mounted.

These and further objects of the invention will become apparent from the following description taken in connection with the accompanying drawings.

In the drawings:

Figure l is a fragmentary perspective view of an armored vehicle provided with the gun control system of this invention.

Figure 2 is a fragmentary side View showing the arrangement of one of the gun turrets.

Figure 3 is a diagrammatic drawing of the gun control system carried by the turrets.

Figure 4 is an enlarged view of the lost motion device shown in Figure 3.

Figure 5 is an enlarged view of the azimuth control cam shown in Figure 3.

Referring first to Figure 1, there is shown the upper portion of a military vehicle I provided with a pair of gun turrets 2 and 3 and three sighting periscopes, t, 5 and 6. Each of the turrets is provided with a gun I, 8, each turret being rotatable about its vertical axis to position its gun in azimuth, and each gun being mounted in its turret for swinging about a horizontal axis transverse of the gun for positioning the gun in elevation.

Figure 2 shows the construction of one of the turrets, the other being substantially identical, except reversely arranged. The turret 2 includes a circular base plate 9 supported for rotation about its vertical axis by suitable anti-friction bearings [0 carried by a stationary supporting ring H rigidly connected to the top plate I2 of the vehicle.

Plate 9 is provided with a pair of generally upstanding plates I3 of generally triangular shape. Pivotally supported between these plates I3 is a gun cradle assembly M of generally semicylindrical form, having trunnions i5 carried by suitable bearings 16 in the upper portion of plates i3. Gun 1 is rigidly carried by the cradle assembly, projecting outwardly as shown through the curved end wall thereof.

To elevate the gun about its transverse trun nion axis, a rotary hydraulic motor ii is provided, which through shaft I 8, bevel gears 19 and 20, and shaft 2 I, drives a pinion 22 meshing with an arcuate rack 23 on one side wall of the cradle assembly as shown in Figures 1 and 3.

To rotate the gun and turret about the vertical 3 turret axis, a second rotary hydraulic motor 24 is provided, which, through shaft 25, and suitable gearing (not shown) drives a pinion 26 meshingwith a ring gear 21 formed on the supporting ring I Motors I1 and 24 are adaptedto be rotated in either direction and at any desired speed, and may be operated individually or simultaneously as the circumstances demand. Hydraulic fluid is supplied to the motors, as shown diagrammatically in Figure 3, by electrically controlled hydraulic pumps 28 and 29, which are adapted to be controlled by solenoids 30 and 3! respectively, each pump being arranged to control the direction and rate of flow of hydraulic fluid to the respective motor to which it is coupled.

Solenoids 30 and 3| are adapted to be energized from a suitable control unit 32 which incorporates conventional manual controls 33 rotatable about axes 34 and 35 to control the movement of the periscope sight 5. The gun I is caused to track the sight by means of a suitable selsyn system (not shown) included in control unit 32. Full description of such a control unit may be found in the co-pending application Serial No. 127,382 entitled Gun Control System.

For the purposes of the instant application, it need merely be pointed out that the magnitude and direction of the currents flowing through the solenoids 30 and 3| at any time will depend on the direction and rate of movement needed to cause the gun to follow the manual controls, the movements of the gun in elevation and azimuth being fed into the control unit as indicated by broken lines 36 and 3'! to provide the desired follow up action. Therefore,- rotation of manual controls 33 about either or both of axes 34 and 35 will cause currents to fiow in solenoids 30 and 3| respectively, the magnitude and direction of such currents being as above described.

Currents induced in solenoid 30 by rotation of handles 33 about axis 34 will cause displacement of armature 38 from its centered position, the direction and amount of the displacement depending on the direction and magnitude of the current flowing in the solenoid. Armature 38 is pivotally connected to one end of rocker arm 39 so that displacement of armature 38 will cause rocker 39 to rotate about its pivot l-Il. Control arm 4|, axial motion of which controls the speed and direction of motion of hydraulic pump 23, is pivotally connected to rocker arm 33 so that motion of the rocker will vary the speed and direction of operation of the pumpand hence of the hydraulic motor ll.

Rotation of handles 33 about axis 35 will induce a current in solenoid 3| as hereinbefore described, causing displacement of armature 42 from its centered position, rotating rocker arm 43 about its pivot 44, and actuating control arm 45 to control the speed and direction of operation of hydraulic pump 29 and hence of the hydraulic motor 24, thus rotating turret 2 in the desired direction.

Arcuate rack 43 is fixed to cradle assembly E4 and meshes with gear 59 so that rotation of the cradle assembly about the axis through its bearings is transmitted through shaft to gear 52, which, in turn, meshes with sliding gear 53;

Element 53, having a threaded hole through its center along a longitudinal axis, is held in a normally centered position with respect to the turret structure by a centering device which includes a spring 85 partially compressed between annular rings 56, the action of the spring serving to hold the rings in place against the turret structure and the plates 5'! which are fixedly carried by element 54.

The threaded portion of shaft 55 is engaged by the threaded hole in the element St so that rotation of the shaft will cause it to move axially with respect to the element.

Gear 53 is carried by the splined portion 41 of shaft 55 so that the shaft is free to move axially, thus leaving the gear at all times in mesh with gear 52 so that rotation of cradle Hi about its bearings is transmitted to the shaft, causing it to move axially through threaded element 54, and giving shaft 55 a given normal axial position for any given elevation angle of gun 1.

Cam 2% is fixed to the supporting ring II and provides a limit for the axial motion of shaft 55 in one direction, the turret structure providing a stop 48, as shown in Figure 3, to limit shaft movement in the opposite direction, continued rotation of the shaft after striking either of the limits causing motion of element 53 against the action of spring 85 due to the interaction of the threads 85 and the threaded hole through the element.

Cam M3 is so shaped in relation to the contour of the vehicle that rotation of turret 2 in aximuth will cause cam it-3 to displace shaft 55 from its normal position by acting against the end of the shaft whenever the elevation of the gun needs to be changed to prevent it from striking any portion of the structure of the vehicle, such as the periscopes or the other gun, projecting into the path of movement of the gun.

Displacement of element 5 3 in the manner described above will cause rotation of shaft 530 by means of bevel gears 58 and 59, gear 58 meshing with rack G! which is an integral part of element 55. Gear 62 is fixed to the end of shaft 50 and rotates therewith, causing rotation of screw 553 by means of gear t4, shaft 65, and bevelgears 38 and 3?, gear 5'! being fixed to the end of screw 63.

Elevation control stop 658 contains a slot 69;

the sides of which act to limit the motion of rocker arm 39. Screw E53 is engaged by a threaded hole through stop 53 so that rotation of the screw will cause stop 63 to move along the axis of the screw.

Rotation of bevel gear 62 also causes rotation of bevel gear It and shaft H. Mounted on the end of shaft H is a disc 12 which carries a pin 13 arranged to engage disc segment 74 which'is 13 arranged to engage disc segment 74 which is of fixed to the end shaft 15 and is mounted coaxially with shaft ii, the above described arrangement, as shown in Figure 4, constituting a lost motion device it which will allow a predetermined amount of rotation of shaft H before the rotation is transmitted to shaft 75. One end of spring 1'! is fixed to the turret structure and the other end is pinned to shaft '55 so as to return the shaft to its normal position when shaft H Cam :13, as shown in Figure 5, is equipped with" upper and lower cam surfaces 82 and 83 which serve to limit the motion of rocker arm 43; If rocker at has been displaced from its centered position by action of solenoid 3|, and cam-18 is caused to rotate by displacementof elementi54,

the appropriate cam surface will act to move the rocker back toward its centered position, thus actuating control arm 45 to slow down or stop pump 29 depending on the extent of the rotation of cam 18.

In operation, if handles 33 are rotated to depress the gun I, the movement of gun cradle 14 will cause rotation of shaft 55, as previously described, resulting in axial movement of the shaft through element 54 toward cam 46. As the gun approaches the lower limit of its travel for the azimuth position which it then occupies, the end of shaft 55 will strike the portion of cam 46 corresponding to the azimuth position of the gun, and any further rotation of the shaft, caused by continued depression of the gun, will cause displacement of element 54 against the action of spring 85. The resulting rotation of shafts 613 and 65 will cause stop 68 to move so that the side of slot 69 will force rocker 39 to a neutral position, overriding the action of solenoid 33, and actuating control arm ll to stop the operation of pump 28, thereby preventing any further depression of the gun. Rotation of shafts 60 and H is not transmitted to shaft because of lost motion device 15, leaving control of the azimuth motion of the turret unaffected. 1

Similarly, elevation of the gun I will cause axial movement of the shaft 55 toward stop 48, and continued elevation of the gun after the shaft strikes the stop will cause the reverse of the motion described above, moving stop 68 so as to force rocker 39 to its neutral position, thus stopping the operation of pump 28 and establishing an upper limit for the elevation of the gun. Lost motion device l6 will again prevent the rotation of shaft H f rom being transmitted to shaft 15'.

If handles 33 are displaced about both of the axes 34 and 35 simultaneously, so that the gun is being depressed and swung in azimuth at the same time, armatures 30 and 3| will be displaced so that the far ends of rockers 38 and 43 are moved toward the limits of travel allowed by elevation control stop 68 and azimuth control cam 18 respectively, the position of the rockers being proportional to the speed of ope-ration of the elevation and azimuth motors. As the gun 1 approaches a portion of themounting structure which extends into the path of the gun barrel, the contour of cam 56 will cause shaft 55 to be displaced axially, carrying with it element 54, the movement being transmitted as previously described to move stop 68, which in turn forces rocker 39 toward its neutral position, overriding the action of solenoid 30 and reducing the speed of elevation motor I'l. At the same time, the rotation of shaft til is transmitted to shaft H, but disc 12 will not have rotated far enough for pin 13 to engage segment 14, so that shaft 15 is not rotated and the position of cam 18 remains unchanged, allowing the turret to continue to rotate in azimuth while the speed of the gun in elevation is being diminished. As gun I continues to approach the obstacle, cam 46 will move shaft 55 farther to the left so that stop 68 continues to move rocker 39 until it reaches its midpoint, thus actuating control arm 4| to stop pump 28 and elevation motor l1. At this point shaft H will have rotated far enough for pin 13 to engage segment 14. Continued rotation of the turret in azimuth will cause cam 46 to move shaft 55 still further to the left, continuing the rotation of shafts 60 and 65 and the movement of stop 68 so that rocker 39 carries control arm 4| far enough to reverse the operation of pump 28, and the simultaneous rotation of shaft II will result in rotation of shaft 15, pin- 13 of lost motion device IE being now engaged with segment M. The rotation of the shaft 15 will be transmitted to cam 13 through bevel gears 79 and 89, the resulting rotation of the cam moving rocker 43 toward its mid-position, the rocker acting to move control arm 45 towards its stop position, overriding the action of solenoid 3|, and slowing the rotation of the turret to a value low enough to give the elevation motor time to elevate the gun far enough to clear the obstacle.

As the top of the obstruction is reached, the shape of cam 4.5 will allow shaft 55 and element 54 to move partly back to a centered position, reversing the rotation of shafts (50 and 65, and moving stop 58 back far enough to allow the action of solenoid 30 to move rocker 39 to its neutral position, thus stopping the elevation movement of the gun. At the same time, reverse.

rotation of shaft will rotate shaft H and disc 12, allowing spring H to rotate shaft 15 back to its normal position, thereby returning cam 18 to its normal position and allowing solenoid 3! to displace rocker t3 and restore azimuth motion to the turret so that the gun is moved across the top of the obstacle.

As the far side of the obstacle is reached by the gun, the shape of cam 4-5 will allow shaft 55 and element 54 to move until element 54 is in its normal centered position, the resulting rotation of shafts 5B and -55 moving stop 58 back'to its normal position, and restoring full control to solenoid 30. At the same time, the rotation of shaft 65 results only in rotation of shaft El and disc 12, since the segment M will be maintained in its neutral position by the spring ll. to no longer acting to modify the motion of the gun, solenoids 30 and 3! will act to bring the gun back into alignment with the periscope sight 5, the movements of the sight having at all times remained under the control of the operator.

As is apparent from the foregoing description, v

the path of the gun as it moves in any direction toward an obstacle extending into its path may be modified as desired b designing the cam 46 and the lost motion device 'It to modify the rate of motion in azimuth, and the rate and direction of motion in elevation, so that the gun may be given any path required to clear an obstacle regardless of the motion called for by the displacement of the manual controls 33, control over the guns movements being returned to the operator once the obstruction is cleared. The gun path so obtained therefore, may be made to conform closely to the shape of any obstacle in the path of the gun, thus minimizing the area into which the gun cannot be aimed.

Although only one embodiment of the present invention has been shown and described, it is obvious that the principles involved are adapted to other applications and many modifications could be made without departing from the spirit and scope of the appended claims.

We claim as our invention:

1. A gun control system for a gun mounted for angular adjustment about substantially perpendicularly related azimuth and elevation axes, power means for swinging said gun about said axes whereby said gun has a field of fire coverage over a predetermined sector of space about said gun, control means normally controlling the operation of said power means for pointing said gun With cam in any desired direction within said sector, a shaft mounted on said turret for axial movement and axially movable responsive to the elevation movement of said gun to assume a given normal axial position for any given elevation angle of said gun, means responsive to the position of said gun in azimuth to displace said shaft axially from said normal position if said gun is depressed below a predetermined elevation angle, which may be different for difierent positions of said gun in azimuth, means responsive to the displacement of said shaft from its normal position to override the action of said normal control means and to modify the operation of said power means so as to limit the angle to which the gun may be depressed.

2. A gun control system for a gun mounted for angular adjustment about substantially perpendicularly related axes, power means for swinging the gun about said axes whereby said gun has a field of fire coverage over a predetermined sector of space about said gun, control means normally controlling the operation of said power means for pointing said gun in any desired direction within said sector, structure normally projecting into said field of fire coverage, an element having a threaded hole therethrough, resilient means urging said element into a normally centered position, a shaft having a portion thereof threaded and adapted to be engaged by said threaded element so that rotation of said shaft will cause relative axial movement between said shaft and said element, means responsive to the elevation movement of said gun to rotate said shaft about its longitudinal axes so that said shaft will tend to'assume a given axial position for each position of said gun in elevation, a fixed cam to limit the axial motion of said shaft in one direction, said limit varying with the contour of said cam so that rotation of said gun in azimuth while said gun is depressed below a predetermined angle will displace said threaded element from its normal position, the amount of displacement being dependent upon the position of said gun in elevation relative to its lower limit, means responsive to the displacement of said threaded element to override the action of said normal control means and operate said power means to modify the path of said gun so as to clear said projecting structure.

3. A gun control system for a gun mounted for angular adjustment about substantially perpendicularly related axes, power means for swinging said gun about said axes whereby said gun has a field of fire coverage over a predetermined sector of space about said gun, control means norm-ally controlling the operation of said power means for pointing said gun in any desired direction within said sector, means responsive to the elevation angle of said gun comprising a shaft mounted for axial movement and movable responsive to elevation movement to assume a given normal axial position for any given elevation angle of said gun, a cam operative responsive to azimuth movement of said gun to displace said shaft axially from its normal position if said gun is depressed below a predetermined angle for any particular azimuth position of said gun, means responsive to the displacement of said shat to override said normal control means and to modify the operation of said power means whereby to vary the speed of said turret in azimuth and to vary the speed and direction of the motion of said gun in elevation in accordance with the amount of such displacement so that said gun is prevented from moving into a position below a predetermined path defined by the shape of said cam regardless of the motion called for by said normal control means.

4. A gun control-system for a vehicle having a turret mounted'thereon for rotation in azimuth about a generally vertical axis and a gun pivotally carried by said turret for angular adjustment in elevation, power means for rotating said turret and for swinging said gun in elevation whereby said gun has a field of fire-coverage over apredetermined sector of space about said turret, said vehicle including structure normally projecting into said field of fire coverage, acontrol armoperative to vary the speed and direction of operation of said gun elevating'means, a second control arm operative to vary the speed and direction of operation of said turret rotating. means, control means normally controlling. the operation of said control arms; means responsive 'to the elevation angle of said gun adapted to assume a given normal position for any given elevation angle of said gun, means responsive to azimuth movement-of said gun to displace said elevation angle responsive means from a normal position, the amount ofdisplacement being determined by the position of said gun in elevation with respect to its position in azimuth, means actuated responsive to such displacement of said elevation angle responsive means and operable to move into contact withthe first of said control arms, overriding the action of said normal control means, and modifying the speed and direction of operation of said-gun elevating means in accordance with the amount-of displacement of said elevation angle responsive means, and means responsive only to displacement of said elevation angle responsive means in'exc-ess of a predetermined minimumand operable to move into contact with the second of said control arms, overriding the. action of said normal control means and modifyi-ngthe speed of operation of said turret rotating means, the extent of the modification depending on theamount of displacement of said elevation angle responsive means, so that said gun is moved in a path to clear said projecting structurewhen said normal control means are operated to move said gun through a position into which said projecting structure extends.

References Cited in the file of thisipatent UNITED STATESPATENTS.

Number Name Date 2,415,967 Pontius Feb. 18, 1947 2,483,385 Humphrey Sept. 27, 1949 2,586,982 Naughler et a1 Feb. 26, 1952 2,633,060 Topham et al Mar. 31, 1953,

FOREIGN PATENTS Number Country Date 565,050 Great Britain Oct. 25, 1944 574,415 Great Britain Jan. 4, 1946 

